<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
			function sum(a,b){
				return a+b;
			}
			
			let sum1=function(a,b){
				return a+b;
			}
			
			let sum2=(a,b)=>{
				return a+sum1(1,sum(1,2));
			};
			
			
			console.info(sum2(1,100));
		</script>
	</body>
</html>